- Urgent referral should be made where the knee is locked (from possible displaced bucket handle meniscal tear) or in the younger patient (less than 30) where there is a good history of acute meniscal tear (e.g. getting up from squatting). Acute tears in the younger patient may be amenable to meniscal repair which should be performed in a timely manner.
- Pain may be due to secondary effects, rather than the tear itself
- Pain alone may not be a good indication for surgery.
- Bucket handle tears and unstable large peripheral tears are typically treated surgically.
- Peripheral undisplaced tears may be considered for repair, particularly if they are recent and in younger patients, however we do not know if repair changes the natural history of such tears.
- Unstable flap tears with mechanical symptoms (clicking, catching) and/or giving way should have a trial of conservative management (around six months is appropriate) as the flap of cartilage can be cleaved off over time with resolution of symptoms.
Degenerative meniscal tears (Cartilage weakens and wears thin over time). Management is conservative ,unless there is a large unstable fragment of cartilage with a good history of true locking (recent evidence: surgery no better than leaving alone) - routine referral MSK physiotherapy.
- Pain
- Stiffness and swelling
- Catching or locking of knee
- The sensation of knee "giving way"
- Reduced range of motion
Parameniscal cysts
- Cysts adjacent to a meniscus where fluid escapes through a meniscal tear and forms a cyst.
- May or may not be painful.
- Tend to be either anterolateral or posteromedial. Anterolateral cysts can irritate the adjacent infrapatellar fat fad producing inflammation (with localised oedema on MRI scan) and pain. Posteromedial cysts may irritate the capsule and MCL.
- The results of surgery are often disappointing with many patients either no better or worse off.
- Our recommendation for parameniscal cysts is one-year trial of conservative management. For those with symptoms persisting for more than a year, or for large significantly symptomatic posteromedial parameniscal cysts, we are happy to see to discuss surgical management.
Chondral defects
- Partial thickness chondral defects should not cause pain and there is no specific medical or surgical treatment required.
- Acute full thickness chondral injuries may be diagnosed on an MRI scan or at time of knee arthroscopy. These may fill in with fibrocartilage over time and even if they do not, they may not cause significant pain. The presence of a full thickness chondral injury likely increases the risk of subsequent progressive osteoarthritis over time but there is no evidence that any surgical or medical intervention alters the natural history. Cartilage regeneration surgery is therefore not indicated for acute chondral injuries.
- Acute osteochondral fractures may occur with traumatic knee injuries, particularly ligamentous injuries and dislocations. A common scenario is an osteochondral fracture of the lateral femoral condyle or under surface of the patella occurring with a patellar dislocation. The bony fragment is usually apparent on plain x-rays however the extent of associated hyaline cartilage injury may not be appreciated.
- MRI scans can clarify the size of the lesion and the location of any surface damage / donor site.
- Where there is a sizeable osteochondral fragment, particularly from a weight bearing area of the joint, surgical fixation will be considered.
- Where a loose osteochondral fragment is identified but it is not amenable to fixation, arthroscopic removal is indicated to prevent surface damage from the loose fragment of bone. Acute osteochondral fractures should therefore be referred to the Acute Knee Injuries Clinic.
- Purely cartilaginous fragments from acute chondral injury identified on MRI are best left alone and are typically engulfed by the surrounding soft tissues. They are removed if found at time of arthroscopy.
- Chronic (osteo)chondral defects can be a source of ongoing pain in the knee. They may be a consequence of a previous contusion or impaction injury (see above) or a consequence of Osteochondritis Dissecans (see above) during adolescence (which may not have previously been diagnosed or symptomatic).
- Symptomatic isolated (osteo)chondral defects are quite uncommon. There is considerable controversy regarding the appropriate management of symptomatic osteochondral defects and the cost of surgical treatment (cartilage regeneration) varies greatly. The results of surgery are highly variable with some being worse off.
- At least one year with activity modification should have passed since any injury or flare-up of pain to allow the bone marrow oedema to settle.
- Referrals for consideration of surgical management of isolated osteochondral defects which fail to settle with conservative management will be vetted to the Soft Tissue Knee Clinic. Those with generalised or multiple areas of chondral loss secondary to joint degeneration, or with coexisting irreparable meniscal injury will not be considered for cartilage regeneration surgery.
- Cartilage Regeneration surgery is controversial, has unpredictable outcomes with some patients being worse off after surgery. Such surgery is likely to be ineffective and is not appropriate for large lesions, lesions of the patellofemoral joint (patella or trochlea) or when there are degenerative / OA changes.